<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        ul{
            list-style-type: none;
        }
        ul li:first-child{
            background-color: green;
        }
        ul li:last-child{
            background-color: pink;
        }
    </style>
</head>
<body>
    <ul>
        <li>第一</li>
        <li>第二</li>
        <li>第三</li>
        <li>第四</li>
        <li>第五</li>
    </ul>
</body>
</html>